I recieved this information from the landscape architect, Scott Lankford.

The plant in the horse trough fountain is known as Sweet Flag Grass. The Latin name is Carex Elata and the variety is Bowles Golden or Aurea. It is also known as Acorus gramineus ogon 'aurea' or 'bowels golden' and is planted in shallow water in a pot. Or it can be planted directly along a natural water edge at about 6" deep.

A couple of other water "grasses" that will work are:
Iris Laevigata, blue water iris
Scirpus tabernaemontani 'zebrinus', zebra rush
Cyperus longus, sweet galingale

I suggest building a pond using 30 ml. butyl rubber liner over a smooth base. Cover with 4-6" round river rock. Bury edges of liner. Set any focal rock on top of liner. Do not cut liner and try to form around rock. Often the liner will be laid over old carpet to help protect the bottom of it from any sharp objects.

I hope this helps.
Dan

This looks awesome! What is the "gravel" or rock that is used as the walkways? Thanks

The gravel is a 5/8 "- dark Skagit grey, laid over structural fabric that the edging block is glued to. This keeps it in plane and level. Scott Lankford was the landscape architect for this project and you can check out his Houzz site: ww.houzz.com/pro/scottlankford/lankford-associates-landscape-architects.

Thanks for asking !

Dan